that's clear Harry - and if the sender that's attached to your gauge doesn't fit the hole where the manual shows it usually is, I would take that to mean yours is different because the head [or engine] is not original to the truck ..... also I'd expect that the original sender wouldn't have a long enough tube to reach the stat housing - PO changed the gauge?
I doubt you'll find any adapter to go from coarse to fine thread in the same diameter hole, and I doubt the factory would have had one there .... next step?
Bill
